In this outlook we describe what could be the next steps of the direct characterization of habitable exoplanets after first the medium and large mission projects and investigate the benefits of the ...spectroscopic and direct imaging approaches. We show that after third and fourth generation missions foreseeable for the next 100 years, we will face a very long era before being able to see directly the morphology of extrasolar organisms.
The SAE FCV Safety Working Group has been addressing fuel cell vehicle (FCV) safety for over 7 years. The initial document, SAE J2578, was published in 2002. SAE J2578 has been valuable to the FCV ...development with regard to the identification of hazards and the definition of countermeasures to mitigate these hazards such that FCVs can be operated in the same manner as conventional gasoline IC-powered vehicles. The document is currently being updated to clarify and update requirements so that the document will continue to be relevant and useful in the future. In addition to developing draft revisions to SAE J2578, the working group has updated SAE 766 and is developing a new recommended practice on vehicular hydrogen systems (SAE J2579). The documents are written from the standpoint of systems-level, performance-based requirements. A risk-based approach was used to identify potential electrical and fuel system hazards and provide criteria for acceptance. As a recommended practice, documents often describe approaches that may be used to mitigate potential risks, but the use of design-prescriptive margins and requirements are minimized in order to still facilitate rapid advances by the industry. The following sections describe critical areas of vehicle safety that have been addressed by the SAE FCV Safety Working Group.
Four cases of benign cystic mesothelioma are described. The disease affects young white women (mean age, 30 years), and they present with chronic pelvic pain. At laparoscopy or laparotomy, multiple ...cysts ranging in size from 0.5 to 4 cm in diameter and containing clear fluid are seen. The disease commonly affects the pelvic organs and/or omentum. With the electron microscope, the cell of origin of this proliferative process is shown to be the mesothelial cell. The disease has been previously described under a variety of terms. There seems to be a tendency for recurrence, but no malignant potential is apparent. Treatment may be conservative with preservation of pelvic organs. Benign cystic mesothelioma should be considered in the differential diagnosis of cystic lesions of the female genital tract.
After Earth's origin, our host star, the Sun, was shining 20 to 25 percent less brightly than today. Without greenhouse-like conditions to warm the atmosphere, our early planet would have been an ice ...ball and life may never have evolved. But life did evolve, which indicates that greenhouse gases must have been present on early Earth to warm the planet. Evidence from the geologic record indicates an abundance of the greenhouse gas CO2. CH4 was probably present as well, and in this regard methanogenic bacteria, which belong to a diverse group of anaerobic procaryotes that ferment CO 2 plus H2 to CH4, may have contributed to modification of the early atmosphere. Molecular oxygen was not present, as is indicated by the study of rocks from that era, which contain iron carbonate rather than iron oxide. Multicellular organisms originated as cells within colonies that became increasingly specialized. The development of photosynthesis allowed the Sun's energy to be harvested directly by life forms. The resultant oxygen accumulated in the atmosphere and formed the ozone layer in the upper atmosphere. Aided by the absorption of harmful UV radiation in the ozone layer, life colonized Earth's surface. Our own planet is a very good example of how life forms modified the atmosphere over the planets' life time. We show that these facts have to be taken into account when we discover and characterize atmospheres of Earth-like exoplanets. If life has originated and evolved on a planet, then it should be expected that a strong co-evolution occurred between life and the atmosphere, the result of which is the planets' climate.
Liposomes containing neutral glycolipids with a terminal glucose or galactose, when injected intravenously, prevented the appearance of erythrocytic forms of malaria (Plasmodium berghei) in mice ...previously injected with sporozoites. Inhibitory glycolipids included glucosyl, galactosyl, or lactosyl ceramide. Inhibition was not observed with liposomes containing ceramide, phosphocholine ceramide, sulfogalactosyl ceramide (sulfatide), or ganglioside G$_{M1}$. Liposomes containing glycolipids did not inhibit infection transmitted by injecting blood containing erythrocytic stages of malaria. These results may have therapeutic implications in the treatment of malaria. Analysis of the mechanism of interference with the life cycle of malaria by liposomal glycolipids may yield information about the interactions of parasites with cellular membranes.
A 3-day-old neonate became acutely and irreversibly paraplegic below L1/L2 after umbilical artery catheterization. The paraplegia was attributed to infarction of the spinal cord because of thrombosis ...of the artery of Adamkievicz or injection of drugs through the catheter into the spinal cord circulation. Catheterization of a more peripheral artery or placement of the umbilical catheter tip at a lower level in the aorta may prevent similar complications.
We present far-infrared spectra and maps of the DR21 molecular cloud core between 196 and 671 microns, using the Herschel-SPIRE spectrometer. Nineteen molecular lines originating from CO, 13CO, HCO+ ...and H2O, plus lines of N II and CI were recorded, including several transitions not previously detected. The CO lines are excited in warm gas with Tkin ~ 125 K and nH2 ~ 7 x 10^4 cm-3, CO column density N(CO) ~ 3.5 x 10^18 cm^-2 and a filling factor of ~ 12%, and appear to trace gas associated with an outflow. The rotational temperature analysis incorporating observations from ground-based telescopes reveals an additional lower excitation CO compoment which has a temperature ~ 78 K and N(CO) ~ 4.5 x 10^21 cm^-2. Astronomy & Astrophysics HERSCHEL special Issue, in press.
The Spectral and Photometric Imaging Receiver (SPIRE), is the Herschel Space Observatory`s submillimetre camera and spectrometer. It contains a three-band imaging photometer operating at 250, 350 and ...500 microns, and an imaging Fourier Transform Spectrometer (FTS) which covers simultaneously its whole operating range of 194-671 microns (447-1550 GHz). The SPIRE detectors are arrays of feedhorn-coupled bolometers cooled to 0.3 K. The photometer has a field of view of 4' x 8', observed simultaneously in the three spectral bands. Its main operating mode is scan-mapping, whereby the field of view is scanned across the sky to achieve full spatial sampling and to cover large areas if desired. The spectrometer has an approximately circular field of view with a diameter of 2.6'. The spectral resolution can be adjusted between 1.2 and 25 GHz by changing the stroke length of the FTS scan mirror. Its main operating mode involves a fixed telescope pointing with multiple scans of the FTS mirror to acquire spectral data. For extended source measurements, multiple position offsets are implemented by means of an internal beam steering mirror to achieve the desired spatial sampling and by rastering of the telescope pointing to map areas larger than the field of view. The SPIRE instrument consists of a cold focal plane unit located inside the Herschel cryostat and warm electronics units, located on the spacecraft Service Module, for instrument control and data handling. Science data are transmitted to Earth with no on-board data compression, and processed by automatic pipelines to produce calibrated science products. The in-flight performance of the instrument matches or exceeds predictions based on pre-launch testing and modelling: the photometer sensitivity is comparable to or slightly better than estimated pre-launch, and the spectrometer sensitivity is also better by a factor of 1.5-2.
